3 Reasons Why Your iPhone Messages Are Green On Other iPhones
Chances are if you’ve ever owned or used an iPhone, you’re familiar with your outgoing text messages appearing in blue bubbles. Sometimes. Other times, though, they’ll show as green instead. So what’s the difference?
In general, blue text bubbles indicate that you’re using Apple’s built-iniMessage app(which comes standard and is the default for most iPhones) to contact someone else who’s also using iMessage on an Apple device. Green text bubbles, on the other hand, mean this isn’t the case.

Seeing green text bubbles instead of blue is the result of one of a few potential hiccups between device connections, but you don’t need to worry if you see them. Unless a message fails to send, in which case your iPhone will let you know about it, your texts are still getting through. It’s just that they’re getting through viaSMS (Short Message Service)or MMS (Multimedia Messaging Service) instead of iMessage. Though SMS texts do lack theend-to-end encryptionsupplied by iMessage.
This is most often the result of using your iPhone to text someone who isn’t using an Apple device, but there are other possible causes.

Turn on iMessage
One possible reason for unexpected green texts is that the iMessage feature itself was somehow shut off. In this case, the app would still function, but without attempting to send your messages via Apple’s proprietary system.
With iMessage turned on for both parties, you should begin to see blue texts again. Though if your texts are still green, there’s likely a different cause.

New device setup
If you or the person you’re messaging has recently switched to a new iOS device, it’s possible that something in the setup process caused a conflict with iMessage.
Beyond that, the problem could actually be with iMessage itself — or its connection to the internet.
iMessage issues
The most likely scenario — especially if your texts aren’t normally green when you correspond with the same contact — is that something is wrong with iMessage. This can be an issue with your app, the recipient’s app, or both depending on the situation.
If iMessage continues to send your texts as SMS, it’s also possible that the service itself is experiencing problems. You can check Apple’s officialSystem Statuspage to ensure, and if it turns out iMessage is down all you can really do is wait.